OAuth implementation using Spring Security

OAuth 2.0 is a way of securing APIs. Spring Security provides Spring Cloud Security and Spring Cloud OAuth2 components for implementing the grant flows we discussed earlier.

We'll create one more service, a security-service, which will control authentication and authorization.

Create a new Maven project and follow these steps:

1. Add the Spring Security and Spring Security OAuth 2 dependencies in pom.xml:

 <dependency> 
   <groupId>org.springframework.cloud</groupId> 
   <artifactId>spring-cloud-starter-security</artifactId> 
</dependency> 
<dependency> 
   <groupId>org.springframework.cloud</groupId> 
   <artifactId>spring-cloud-starter-oauth2</artifactId> 
</dependency> 

2. Use the @EnableResourceServer annotation in your application class. This will allow this application to work as a resource server. The @EnableAuthorizationServer annotation is another annotation we will use to enable...